@book{30983,
	author = {Mengual, Pilar,},
	title = {Step 7 :},
	publisher = {Marcombo S.A.,},
	year = {septiembre 2009.},
	series = {Marcombo Formación},
	address = {Barcelona :},
	edition = {Primera edición.},
	url = {https://login.zproxy.cun.edu.co/login?url=https://www.digitaliapublishing.com/a/17122/}
}